[refs #579] fix checking path

app/controllers/projects/comments_controller.rb

@@ -68,7 +68,8 @@ class Projects::CommentsController < Projects::BaseController
       @comment.data[:to_commit], @comment.data[:from_commit] = to_commit, from_commit
 
       diff = pull.diff repo, to_commit, from_commit
-      return false unless diff_path = diff.select {|d| d.a_path == params[:path]}
+      diff_path = diff.select {|d| d.a_path == params[:path]}
+      return false if diff_path.blank?
       comment_line = params[:line].to_i
       return false if comment_line == 0 # NB! also dont want create comment to the diff header